Copyright

Works in the public domain are not protected by copyright and may be freely used by everyone. Once a work enters the public domain, it cannot be reclaimed by the original copyright owner. Reasons that these works are not protected include:

• Work does not meet the requirements for copyright.
• Copyright for the work has expired.
• Author/creator failed to satisfy statutory formality to perfect the copyright.
• Work was created by the federal government (does not apply to works by other government entities, grant recipients, or contractors).

Cornell University Copyright Information Center offers a Copyright Term and the Public Domain in the United States chart to help you determine works that might fall within the public domain.